Scientific Curiosity
by MegaBadBunny
Summary: Rose's perfectly innocent question about the Doctor's birthday leads to a bit of not-quite-so-innocent conversation. A fic fill for the prompt "birthday fluff."


"Have you got a birthday?" Rose finds herself asking one day.

It isn't completely out of the blue. They've just spent the last twenty-two hours celebrating her birthday, after all.

(Twenty-two hours in Space Disney. Practically the whole day. Down to the minute. He woke her up at 4:21 am. She was...not entirely pleased.)

(She might have hit him in the face with a pillow.)

Now, they're watching telly in the library back on the TARDIS, he in his suit, Rose in a commemorative Space Disney tee-shirt; a bowl of popcorn sits nestled between them, a blanket is tossed over them, and two pairs of feet are propped up among them. His heels, clad in mismatched socks, rest on a weathered wooden coffee table (Rose can't decide if it was nicked in some revolutionary war in some distant future, or if it is simply an IKEA purchase gone horribly, horribly wrong); Rose's ankles have found themselves stretched along the length of the couch until her legs have mysteriously draped themselves over his.

(The mystery isn't _how_ they got there—Rose was content to sit mostly in her own space, her bare feet on the coffee table next to his, toes wriggling and turning pink with cold, but then suddenly he was reaching over and saying something about "Well, put them under the blanket, then," and then before she knew it, her legs were under the blanket and in his lap—the mystery is _why_.)

(Because the blanket is hardly a sufficient explanation for why his hand is resting on her knee and alternately rubbing in circles and drumming out an absentminded beat.)

(It's all very distracting.)

It isn't that Rose minds the lack of personal space. She isn't very good about that herself. She's always been quick to hold hands, to give hugs, to snuggle up on chilly nights, to offer comfort, commiseration, camaraderie in the form of physical contact. The closeness of other people has never bothered her, not unless they're smelly, or lads leering at her on the bus, or just overall rude.

(But only certain kinds of rude. She can make exceptions.)

But at some point the popcorn bowl is empty (and that isn't exactly a mystery either, not with both of them licking the salt and butter off their fingers) and the hand that isn't tracing over the lines of her kneecap has now draped over the back of the couch behind her. And even that wouldn't give her pause, normally, because this Doctor seems to share her problems with personal boundaries, hands itching to hold hers, to grab her by the waist, guide her by the small of her back, cinch around her shoulders. He's very touchy, this Doctor, to the point where Rose has wondered if he's just looking for excuses to come into contact with her.

(God knows she's guilty of the same in reverse.)

At least, she has wondered that until today, until just now, when she realizes that he's probably not thinking about any of it at all. There's no plan here, no map. Not even the kind of haphazard half-plotting that lands them in the nineteenth century instead of the twentieth. It's completely unintentional, subconscious, second nature.

Unthinking comfort in contact. Like _couples_ do.

The temptation to completely give in to the illusion is very, very strong, pulling deep in Rose's gut. An undertow of want. It's something Rose tries not to think about very often—he's had hundreds of years in this universe, and seen and done so many things, and he can be so very _alien_ , and what is a simple London shop girl compared to all that?—but it would be so easy to just drop the defenses she's built up over the last year or so. (Or tried to build. She's not a saint. For all that she's able to push this stuff to the background most of the time, she's still lost more than one night of sleep over him.) She could curl up into his side, her head tucked her his chin, her hand resting on his chest. She's so tired after a day of running and laughing; she doubts he would push her away. She doubts he would even mind. It would be so easy to pretend.

At least until she heard and felt the double heartsbeat beneath her, and remembered that if she's figured all this out, then he's only seconds behind.

So she scrambles for a distraction instead, and a question about his birthday is what pops out.

"Of course I have," he replies easily. He's still watching the telly; the light from the screen bathes the dips and planes of his face in a ghostly grey-blue. Alien, indeed. "Everything organic has technically got a date of birth."

"You know what I mean. Like a proper birthday."

The Doctor shoots her a questioning glance, eyebrow raised. "Not everyone needs gifts and cakes and streamers and funny little hats to celebrate a birthday. That's a bit earth-centric, don't you think?"

"I guess it would be a lot of candles," Rose teases.

"Bit of a fire hazard," the Doctor agrees with a grin, and he turns his attentions back toward the television set. A black-and-white film is playing, one Rose vaguely recognizes as something she used to watch with her gramps. A couple dances their way across the screen, the bloke in a tux, the lady in a swirling colorless dress. Rose remembers watching the film as a child and wishing she had that kind of grace. Hell, she still wishes it.

"You know they shot this scene so many times, Ginger's feet started to bleed?" the Doctor asks conversationally. "Nobody made her do it. She was just determined that the dance should be perfect. Ended up bleeding right through her shoes."

His cheeks puff up and he lets the air out with a little _puh_ sound. "Can't agree with the method, but then again, you can't exactly argue with the results, either. This is one of the most beautiful things that will ever be captured on film."

"Hmm, I like to imagine what the colors used to be," Rose says drowsily. She knows he's talking about the dance, not the costumes, but she's too tired to pay much attention to any of it. "You know, in real life, without the black-and-white. Like that dress—" she points to the garment in question, sparkling under the stage lights, "—it's be sort of gold, like a classy vintage champagne color, that sort of thing."

"Nah. It was pink."

"What? Really?"

The Doctor smiles mischievously. "We could always go find out."

Rose is sort of tempted, but then again, she's also smart enough to recognize a diversion when she sees one. (Even if she is dreadfully sleepy.)

"For my birthday?" she asks, matching the Doctor's smile with one of her own.

"Certainly," the Doctor says, jostling his legs in the universal sign that Rose should move hers. She withdraws and he springs up from the couch. "We've still got two hours left. Might as well make the best of them!"

He holds out his hand to help her up. She doesn't take it.

"But what do you want for _your_ birthday?" Rose asks.

The Doctor bounces impatiently on his heels. "Like I said, not everybody celebrates their birthday with a gift."

"Just saying, you've planned a very nice day for me, doesn't seem fair if I don't do the same for you."

"Yes, well." The Doctor rubs the back of his neck. "I might have only thought to do it after I received a very convincing phone call from your mother. Speaking of things that bleed, did you know your ears can?"

Rose's eyes narrow in suspicion. "Mum doesn't have your number. Have you even got a number?"

"Nope! It's all a great big mystery. A conspiracy, even. Possibly on a galactic level." The Doctor reaches down and pulls Rose up by the hands. "We could look into it. Or we could pop over and visit Fred and Ginger in 1936. Or we could even visit a hypervodka distillery in the forty-third century and try their newest flavor. (It's strueberry. A hybrid of a strawberry and a blueberry. You'll love it.) Your birthday, your choice!"

"For another two hours," Rose says.

"For another two hours," the Doctor agrees. He's still holding both of her hands, keeping her close to him. If he emitted much in the way of body heat, Rose would be feeling it right now.

"All right, then. For my birthday, I want..."

The Doctor watches her expectantly. Rose bites her bottom lip. His eyes follow the motion. She reminds herself that it's just because that's what eyes do, they follow movement, it doesn't mean anything.

Blimey. She really shouldn't be around him when she's so sleepy. It's making her vulnerable.

(She was doing _so well_ before today. Really, she was.)

"...to know how you celebrate your birthday," Rose finishes.

The Doctor rolls his eyes and drops her hands. "And she's not giving up," he mutters to himself.

"Oh, come on," Rose says. She's treading dangerous waters and she knows it, but she thinks that maybe, just maybe, she can make it to the shore if she doesn't acknowledge just how deep the ocean goes. "Call it my last present," she continues, and she tilts her head and smiles at him with _that_ smile, the tongue-touched one, that she knows will get her anything she wants.

(She has a few tricks of her own.)

He heaves a sigh and pushes his hands into his pockets. "We don't," he says. "I don't. Celebrate it. There's nothing to celebrate."

Rose frowns. "That's sort of a sad way to look at it."

"Not really. It's actually a very practical way of looking at it. It isn't as if I did anything particularly spectacular when I was born. Other people did all the work. And I wasn't exactly 'born' to begin with, per se."

Before Rose can ask about that, he takes off walking. "And can you imagine the mess with regenerations?" he calls back. "Do you celebrate the day your first regeneration came into existence, or the day your current incarnation did? It's all very messy, not worth the trouble."

Rose's brain and feet are both racing, her brain trying to catch up with his words, her feet following after him in the corridor. "Hang on—what do you mean, you weren't _born_?"

The Doctor clicks his tongue, _tsk tsk tsk_ , and waves a knowing finger. "You've already used up your last birthday present—and on a rubbish request, I might add. You could have seen Fred and Ginger perform in-person."

"Okay, but earlier, you said everything's got a date of birth, and now you're saying that _you_ don't. And it's the same line of query, it still counts!"

"Actually, there's nothing in the rulebook that says we can't still go see them," the Doctor keeps talking, prattling on until they've reached the console room. His voice bounces off the walls all around them. "There isn't even a rulebook at all. We wouldn't be violating anyone's rules. No rulebook, no rules, no reason not to! Hollywood, 1936, let's do it!"

He races up the ramp and bounds around the control desk and starts flipping switches and entering commands into a keyboard. "You know, I always thought they fancied each other a bit and never said anything," the Doctor says. He throws a lever. The TARDIS jolts, beginning its dematerialization sequence, and the Doctor grins down at Rose.

"We could scope it out. An investigative mission to cap off the day! What do you say?"

Rose doesn't say anything. She is a little too tired to go on another adventure right now, wants nothing more than to scoot off to her own warm cocoon of a bed, but she would never tell him that. Instead, she leans back against the wall and crosses her arms. She looks up at him expectantly.

The grin fades off the Doctor's face. "Or not," he says.

He pushes a button, and the time rotor powers down, lights and noise flickering away to their usual bare hum. "Maybe you're too tired," the Doctor suggests.

"I am a little tired of not knowing anything."

"Don't be ridiculous," he scoffs. He waves a hand dismissively. "You know plenty of things. More than most humans. More than a lot of other people, too."

"Yeah, but..."

Rose's heart pounds a desperate beat in her throat. _Stop-stop stop-stop stop-stop_.

"...I still don't really know anything about you," she finishes, and tries not to flinch.

(Any second now, she's going to drown.)

The Doctor is staring at a screen on the console, looking without seeing.

"It's just, it's a pretty small detail, I feel like, and—and you know everything about me, but I don't really know anything about you," Rose continues. "I don't even…"

 _Know your name_ hangs in the air. It's very loud for something that goes unsaid.

His eyes have lost their focus. He's gripping the edge of the desk. Rose can hear his fingers tightening, squeaking against the coral.

Rose is not afraid of the Doctor. But she is afraid for him.

(She thinks it must be very sad, to feel like you can never tell anyone anything, not even your best friend.)

"Okay," she says after the silence becomes too uncomfortable to bear. Her voice is a little shakier than she'd like, because this conversation has made her more nervous than she'll admit. "Actually...I think I'd like to revise my last birthday request. Amend it, or whatever. And ask that you're not, erm."

She laughs. "Not angry with me anymore."

He sends her a sharp look.

"Thanks for the birthday though," Rose says; "It really was a lovely day." She means it. She turns to leave.

"I'm not angry."

The Doctor sounds a little tired himself. Rose risks a glance back at him. His face has gone passive, neutral.

"And Time Lords aren't really born," he tells her. "They're more sort of...made. Grown." The words inch out like someone's pulling them from him. Like someone's pulling teeth.

"Like the TARDIS?" Rose asks, remembering their conversation in the space station on Krop Tor.

"Sort of like that, yeah."

"So there's no, like, pregnancy or anything like that?"

"Not as such, not for a long time now, no."

"So you don't..."

Rose stops herself. She is not about to ask about Time Lord genitalia. She is _not_.

"...have any bits?"

The Doctor's eyes widen in surprise. Rose curses her treacherous mouth, made loose and traitorous by a need for sleep, and feels herself flush as brightly as her namesake.

(What the fuck is wrong with her?)

"Actually, I think I could use that hypervodka right now," she says feebly.

"It's all right, Rose," the Doctor tells her, and is he chuckling under his breath? He stows his hands safely in his pockets once again, and starts back down the ramp to join her. "You're curious. It's natural."

"Right," Rose agrees, nodding. "Curious. You know me. Curious little human. I can't help it. I'm like a cat that way. I just get curious about things."

Now she's the one who's prattling. And he just keeps getting closer. She begs her mouth to stop.

"Curiouser and curiouser," she laughs nervously. The word 'curious' is starting to sound funny, like word soup.

(Please, please don't let him know that she sometimes thinks about his bits. Please, god.)

"Scientific curiosity. Just curiosity for curiosity's sake!"

The Doctor hums. He stops in front of her. "And here I thought you were just overwhelmed by my manly charms."

Rose blinks at him. He winks at her. And now she laughs for real. The Doctor laughs with her.

"That sort of reaction does wonders for a bloke's ego," he says, rubbing the side of his face.

"Yeah, right. Like your ego needs any more stroking," Rose teases, and immediately regrets her choice of words. The Doctor is watching her with no small amount of amusement in his eyes and a smug little smile on his face and _damn him._

(He only _pretends_ not to understand some of this stuff, Rose thinks; he's more human than she gives him credit for.)

(Also, he's entirely too comfortable watching her squirm.)

"So how about it, then?" she asks, forcing herself to look him in the eye, willing herself not to blush any more than she already is. She's already got the ball rolling; might as well give it another push. "It might not be used for its original intended purpose, but do Time Lords, erm, still have the equipment?"

"Just for curiosity's sake?" He's standing very close to her again.

"Just for curiosity's sake. Purely scientific."

"Well, then. If it's in the name of science, how can I refuse?"

The Doctor stands up straight, smoothing out the wrinkles in his suit jacket. "Yes," he tells Rose, "Time Lords are fully intact, with all the normal exterior body structure one would expect from a bipedal, mammalian, humanoid species."

His eyebrow arches, an inquisitive little thing. "Is your curiosity satisfied?"

Rose nods, and relaxes a bit. "My very scientific curiosity, yes."

He smiles at her. "Good."

And when Rose, as much to her surprise as anyone else's, lets out a small yawn, he holds his hand out to her. "And I think that's a good note on which to end the night."

"I'm fine," Rose protests, but she doesn't stop him from leading her back down the corridor, toward her bedroom. "Let's go see Fred and Ginger!"

"Maybe when you haven't been awake for nearly twenty-four hours. It's a thing best appreciated when you're not asleep and drooling on someone's shoulder."

"That only happened once," Rose mumbles. "And it's still my birthday. And you," she points a lazy finger his way, "You never did answer my question, Doctor."

"That being?"

"What do you want for your birthday, whenever it is?"

"You already used up your last gift on a different question, remember?"

"And I don't get take-backs for that sort of thing?" Rose asks. They've arrived at her bedroom, and she feels heavy with the desire for sleep, but she still doesn't quite want the day to end.

"Nope," the Doctor says cheerfully, popping the "p". "You frittered it away on scientific curiosity, I'm afraid."

"I feared as much," Rose sighs, and she pushes her bedroom door open. Her soft, plush bed does seem very inviting and nice, now that she's looking at it. Like a fluffy nighttime cloud. She has made it perhaps three feet into her bedroom when the Doctor speaks again behind her.

"Although I do feel compelled to point out that a real scientist wouldn't just take someone's word on it," he says. "They'd want to find out the truth firsthand."

Rose's heart starts racing in her throat again.

(Is he saying...?)

She turns around, and the look on his face is perfectly innocent. She could very well have imagined those last words, and the heat in them. She is pretty tired, after all.

The Doctor smiles. "Good night, Rose," he says, and the way his mouth forms around her name almost makes her shudder.

"Wait. Seriously though. What do you want for your birthday?" Rose asks, bridging the distance between them before he can turn and leave.

"Seriously?"

Rose nods.

He shrugs. "Don't really need anything, do I? I have you."

The words make Rose feel warm deep in her chest. Yes, she thinks. Yes, he does. The smug bastard. So she stands on her tiptoes and kisses him.

(It doesn't necessarily have to be a romantic kiss, pressed to a friendly area between his mouth and his cheek, but it isn't as chaste as it could be, either, lingering just a little too hard and just a little too long. Her pulse bleats madly in her ears the whole time. And she is very, very satisfied when she stands back and he finally looks, just the slightest bit, like he might be a little bit flustered.)

(Is that a faint tinge of pink in his cheeks?)

"I thought we agreed you used up your last gift," he says quietly.

Rose grins at him. "Who says that was for me?"

He might not be blushing, but he's definitely unsettled, mouth open and eyes blinking just a little too fast. Still, he smiles back at her even as she closes the door on him.

"Happy early birthday, Doctor," Rose tells him.

He nods. He's beaming at her now. "Happy birthday."

8


End file.
